Granted Patent
Utility
US 5,253,720 · App. 07/716,664
Method and apparatus for taking an undisturbed core sample
Inventors:
Steven R. Radford, Haraldur Karlsson, James T. Aumann
Patented Case
View Patent ↗
Granted: Oct 19, 1993
Filed: Jun 13, 1991
Inventors
Steven R. Radford
Haraldur Karlsson
James T. Aumann
Assignee (at issue)
Energy Ventures, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.